Advances in Electrical and Computer Engineering
ISSN 1582-7445 - No 2 / 2004

   EDITOR

  Adrian GRAUR   - Dean of the Faculty of Electrical Engineering
 
 
   ASSOCIATE  EDITORS

  Ştefan Gh. PENTIUC  - Scientific Secretary of the Faculty of Electrical Engineering
  Leon MANDICI   -  Vice-Dean of the Faculty of Electrical Engineering
  Dorel CERNOMAZU  - Professor at the Faculty of Electrical Engineering
 
 
   EDITORIAL  BOARD

 Tudor AMBROS   - Technical University of Chişinău - MOLDAVIA
 Dumitru N. ALEXANDRU   - Technical University Iasi
 Jao Paulo BAPTISTA   - Instituto Politecnico do Porto - PORTUGAL
 Oleg BREKHOV   - Moscow Aviation Institute - RUSSIA
 Mihai CERNAT - "Transilvania" University Brasov
 Cristophe CHAILLOU   - Universite des Sciences et Technologies de Lille - FRANCE
 Mihai CRETU   - Technical University Iaşi
 Luc DE BACKER   - Katholieke Hogeschool Sint-Lieven Gent - BELGIUM
 Timothy HALL   - University of Limerick - IRELAND
 Ileana HAMBURG   -Institute for Technology Gelsenkirchen - GERMANY
 Stefan HOLBAN   - "Politehnica" University Timisoara
 Maria G. IOANNIDES   - National Technical University of Athens - GREECE
 Ioan JURCA   - "Politehnica" University Timisoara
 Eleftherios A. KAYAFAS   - National Technical University of Athens - GREECE
 Mykola KIRICHENKO   - Institute of Cybernetics Kiev - UKRAINE
 Valeriu KRAPIVIN   - Moscow Institute of Radioengineering and ELectronics - RUSSIA
 Ioan LETIA   - Technical University Cluj-Napoca
 Volodymyr MESYURA   - The State Technical University of Vinnitsa - UKRAINE
 John MILNER   - City University London - GREAT BRITAIN
 Radu MUNTEANU  - Technical University Cluj-Napoca
 Jose OLIVEIRA e SA  - Instituto Politecnico do Porto - PORTUGAL
 Carine NAESSENS  - Katholieke Hogeschool Sint-Lieven Gent - BELGIUM
 Costică NITU   - University Politehnica Bucureşti
 Adrian PETRESCU   - University Politehnica Bucureşti
 Mircea PETRESCU  - University Politehnica Bucureşti
 Nicola PITRONE  - Universita degli Studi Catania - ITALIA
 Jean Paul SIX   - Université des Sciences et Technologies de Lille - FRANCE
 Fedir SOPRONIUC   - University of Cernăuţi - UKRAINE
 Gavril TODEREAN - Technical University Cluj-Napoca
 Petru TODOS   - Technical University of Chisinau - MOLDAVIA
 Bernard TOURSEL   - Université des Sciences et Technologies de Lille - FRANCE
 
 

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FEE Info

24 – 29  May 2004
 
 

In 2004 the Faculty of Electrical Engineering organized the 11th edition of the Annual International Students’ Computers Contest “Hard & Soft”. The contest consisted in designing and developing a University Office Management System based on simple and low-cost components as well as network and database technologies. The system allowed students to detect the professors’ presence in their offices and their availability for tutorial activities. The proposed system could support various user types such as students, professors, supervisors or safety managers. Each type of users had a set of access privileges within the system.

Participants: teams from Brasov, Bucuresti, Cernivtsy (Ukraine), Chisinau (Moldova), Galati,  Iasi, Novi Sad (Serbia & Muntenegru), Oradea, Suceava, Timisoara.
President of the jury: Professor Timothy HALL from University of Limerick, the Irish Republic. His team included Ciaran MACNAMEE, Dorel PICOVICI, Kevin JOHNSON from the same university.
 

The prizes were awarded to:
• the “Politehnica” University of Bucharest   -  1st  prize
• the “Stefan cel Mare” University of Suceava  -  2nd  prize
• the “Transilvania” University of Brasov   -  3rd  prize

The 12th edition of the contest will be held in May 16 – 21, 2005.
 
 
 

Professor Adrian GRAUR

Abstract. In this paper, we will analyse optimal uniform quantizer construction method for wide volume range (for variable variance) with the respect to the mean-square error as a performance evaluation measure. Optimality conditions and solutions for optimal number of levels and phase partitions are also presented. We will also consider range width as well as number of representation levels influences on optimal quantizer selection.
Keywords: uniform polar quantizer, granular distortion, variable variance.
 

Abstract. An improved quasi-resonant dc link (QPRDCL) and pulse width modulated (PWM) operation for soft switching inverters are presented. The new QPRDCLI  is introduced, which has been achieved with a PWM control strategy developed for induction motor speed control. Experimental results from a laboratory prototype model are presented. The QPRDCLI waveforms are measured and the inverter efficiency is measured and compared to a hard switched case.

Keywords: QPRDCL, Soft switching, soft switching inverter, PWM, induction motor control.
 
 

Abstract. The electric power industry is currently undergoing an unprecedented reform worldwide. Voltage control and stability problems are now receiving special attention in many modern power systems. The application of modal analysis helps in determining how stable the system is and how much of extra load or power transfer level should be added. When the system reaches the voltage stability critical point, the modal analysis identifies the voltage stability critical areas and elements (buses, branches and generators) which participate in each mode. The paper presents the basis aspects of voltage stability concept, develops the modal analysis theory and investigate a case study results of Reactive Participation Factor (RPF) method.
Keywords: power system, voltage stability, static analysis, U-Q modal analysis, Reactive Participation Factor.
 
 

Abstract. The paper proposes the computer transcription of handwritten Pitman shorthand as a mean of rapid text entry to handheld devices. Handwritten outlines are bound to be variation from writers to writers and it causes pattern recognition to be prone to errors, however these imperfections can be restored by the use of heuristic approach in the interpretation stage. The transcription accuracy can be improved by the combination of three factors: firstly, incorporating contextual knowledge as used by human readers; secondly, applying knowledge of the most frequent words of Pitman shorthand; and finally, adding knowledge of collocation.  Statistical analysis of a Shorthand lexicon is presented and distribution of transcription accuracy based on accuracy of segmentation is discussed in the paper. Experiments using a phonetic Lexicon with 5000 entries show that the approach is efficient and produces a satisfactory transcription accuracy of 94%.
Keywords: Pitman shorthand, unigram approach, shorthand lexicon, most frequently used words
 
 

Abstract. Open source software is becoming the most interesting ‘new’ phenomenon of the entire information technology area, generating a level of interest similar to that of the first moments of the Internet. The impact of open source technology is expected to be quite noticeable in the software industry, and in society as a whole. It allows for novel development models, which have already been demonstrated to be especially well suited to efficiently take advantage of the work of developers spread across all corners of the planet. It also enables completely new business models, which are shaping a network of groups and companies based on open source software development. This paper will look at work carried out on a project to create an effective authoring tool for use within an Irish Higher Education Institution that would allow for the creation and publication of electronic content for modules run within the University.
Keywords: Open Source technology, publishing content, authoring tool, Higher Education, dynamic content.
 

Abstract. In this paper are presented an implementation and algorithm for communication protocol between Telemetry system and sensors in borehole measurement instruments. This protocol is called SIPLOS (Simultaneous Production Logging String) and it is used in Hotwell company as part of larger system for borehole investigations. Protocol between Telemetry tool and Calliper-Fullbore Flowmeter tool is described in details.
Keywords: protocol, Calliper-Fullbore Flowmeter tool, Telemetry tool, measurement, sensors .
 

Abstract. When digital data is sent over a wireless channel, transmission errors may occur.  These errors are for instance caused by interferences in the channel.  To improve the performance of the communication link, error detection and correction codes are used.  Before starting implementing this link, a well-considered choice of forward error correction (FEC) is very important.  In this article instructions are given to help finding the right error correction code for a specific application.
After an introduction on channel models, the typical errors introduced by these channels are given.  The efficiency of error correction codes, like Reed Solomon and convolutional codes, is tested by means of simulations.  First we look at the performance of forward error correction codes for different channels.  Based on the properties of both, the channel and the error correction code, we explain the simulation results..  In this way, a guideline for the choice of a FEC code is presented.
Keywords: wireless, forward error correction, channel model.
 

Abstract. This paper describes the approach for the computer networks intrusions detection based on the artificial neural networks performing the users and processes activities identification. The offered intrusions detection system is adaptable to the different network attacks and allows improve the detection effectiveness.
Keywords: intrusions detection, anomaly, abusing, expert system, artificial neural network
 

Abstract. Dynamic computing environments require adaptive algorithms for load balancing. To increase system flexibility, mobile agents are used for encapsulating tasks. During successive migration phases, those agents have the possibility to explore, to learn and to share information about load. Ant Colony Optimisation metaheuristic is used for routing tasks with high efficiency due to its capacity to store and to learn from system’s history. Finally, this information is used in maintaining an equitable task load for each processing unit. MPI implementations were used to make simulations and comparisons with different deterministic nearest neighbour load balancing techniques. Results have shown some improvements in terms of convergence stability and task distribution compared with classical algorithms.
Keywords: load balancing, agent, Ant Colony Optimisation, metaheuristic.
 

Abstract. The grid computing is a relatively new direction and is a new way of making distributed computing using UNIX based heterogeneous cluster of workstations and supercomputers. In this paper the Nordic countries grid computing initiative is presented.
Keywords: grid computing, Linux, heterogeneous cluster.
 

Abstract. In the complexity theory is notable involving of the iterative functions in behaviour of fractal pattern. Study of the nonlinear equation, treated into iterative techniques, makes the subject of this paper. It consists in a short revue of the most important principles of the fractal calculus and complexity applications in fundamental sciences and technologies. Were been presented also some new ideas of analysis to iterative relations like as named the modified logistic equation. Is shown a relation that can be conducts to performing some studies with valuable results in numeric analysis area. In this paper work is performed a critical analysis about iterative fractal techniques which can conduct to various implemented applications. In bifurcation diagram of logistic map are presented results of the own program run, that is written under C++ programming language. With this occasion we observed some different featuring for some characteristic points by defined domain, in relation with those specified features into published works over subject. The Ising model was be used by our team in designing one bipolar spin-transistor based on the spintronics theory.
Keywords: fractal, iterative algorithm, logistic map, attractor, spintronics theory.
 

Abstract. This article presents an utility meter reading interface application using the Internet as a transmission medium. For energy meters, pulses for every quarter of an hour are counted on a local microcontroller and stored on a EEPROM memory, all demand data being transmitted to the energy dispatcher control unit via the Internet communication embedded microcontroller. We used a combination of low cost microcontrollers to interface the existing meters and the utility balance software. The idea may be applied in power substations but is also useful for medium-size consumers who have multiple exchange points with the energy supplier, equipped with standard meters that are able to provide only free potential relay contacts for billing applications. Using standard Ethernet network communications is also a new idea in this field, all data will be available in real time to the energy management unit using IP transmissions. The application was tested in a real life project and does not interfere with the billing data from the meter memory, so there is no need for other legal approvals.
Keywords:  utility, energy, meter, communications,  interface
 
 

Abstract. One studies the influence of the derivatives of a vector control field with respect to the parameter.
Keywords: vector fields, Variational Equations, nonlinear systems.
 
 

Abstract. FPGA's can be programmed to implement almost any digital circuit beginning with the simplest ones up to new microcontrollers and processors. One of the last fields of interest in developing with FPGA circuits is general SoC  (System On a Chip) architecture. The reasons of the success this type of system has are multiple: unique functionalities and features, lower final costs, reduced number of components, high integration and higher product security. SoC’s can be divided in two distinct categories: commercial and freeware. From commercial SoC’s we can mention the TriCore family produced by Infineon Gmbh with the following peripherals implemented: Ethernet controller,  USB 1.1 module, 1 MultiCAN module with 4 CAN nodes, 3 asynchronous/synchronous serial channels, 2 high speed synchronous serial channels, inter IC (IIC) serial module and  2 high speed Micro Link interfaces. From the freeware SoC’s category we can mention: Wishbone System6800/01, System09 or C-NIT processor.
Keywords: FPGA, SoC, Ethernet, FLASH write, SRAM, synthesis, debug, processor, core.
 
 

Abstract. The aim of this paper is to present a robust and efficient background subtraction technique for real time traffic monitoring and analysis. It is well known that background subtraction techniques have been used in many vision-based interfaces to extract moving objects, but most of these interfaces still suffer from the changes of lighting (highlighting and shadows). The technique we proposed is strong enough in order to deal with changes of lighting and the experimental results shows that it can be used in various vision-based applications that needs real-time segmentation and tracking. The technique we developed was tested with a video sequence taken from a crossroad. The application that was developed produces results available on Intranet.
Keywords: image processing, moving target detection, background subtraction.